Amit Gross

Ben-Gurion University of the Negev | bgu · Zuckerberg Institute for Water Research (ZIWR)

Land desertification, water scarcity, and food security challenges in arid zones are intensifying, driving the need for sustainable agricultural solutions like aquaponics. This study investigated innovative water and energy-saving strategies using an integrated dynamic model for an on-demand industrial aquaponics system in Israel. The model evaluat...

Aquaponics presents promising green technology for food security and climate change. This study investigated the performance and nutrient dynamics in a novel aquaponics with onsite anaerobic treatment compared with conventional decoupled and coupled aquaponics. All systems demonstrated good performance with fish survival rates of >97 %, feed conver...

Decentralized wastewater treatment, specifically onsite treatment, is fundamental to recent wastewater management paradigms. However, onsite solutions often produce inadequate effluent quality for reuse and are ineffective in removing organic micropollutants (OMPs). This study suggests a multistep onsite system for treating wastewater in varying co...

Hydroponics is a resource-efficient system that increases food production and enhances the overall sustainability of agricultural systems, particularly in arid zones with prevalent water scarcity and limited areas of arable land. This study investigated zero-waste hydroponics systems fed by agricultural waste streams as nutrient sources under deser...

A potential change in climate and temperature could strongly affect weather-related crop losses. Using wastelands to grow crops in controlled greenhouse environments could improve global food security and preserve ecosystems. However, the impact of climate change on additional energy and water requirements of greenhouse-horticulture food production...

Hydrothermal carbonization (HTC) is an emerging technology that may potentially address sanitation problems and energy scarcity. However, the significance of the parameters that govern HTC (e.g., temperature and time) is not fully understood, in particular for human excreta. A simplified coalification model was used to describe the 'strength' of th...

Aquaculture is the fastest growing agricultural sector in the world, and the annual aquaculture production reached 82 million tonnes in 2018. Fish feed is the most expensive component of aquaculture. The partial replacement of commercial fish feed with biofloc was evaluated as a dietary ingredient in feed for barramundi (Lates calcarifer), a high-v...

Crop residues, such as toxic tomato plant wastes, often cause environmental and economic burdens. Anaerobic digestion of these residues, which contain hardly biodegradable lignocellulosic content and low C/N (~10), was not thoroughly studied or practiced. This study investigated the impacts of temperature and particle size on anaerobic degradation...

Aquaponics is gaining renewed interest to enhance food security. This study aimed to investigate the performance of a novel off-grid aquaponics system with near-zero water and waste discharge, focusing on the carbon cycle and energy recovery that was achieved by the addition of onsite anaerobic treatment of the solid waste streams. Following a stab...

There is a growing body of knowledge on the persistence of antibiotic-resistant genes (ARGs) and antibiotic-resistant bacteria (ARB) in greywater and greywater treatment systems such as constructed wetlands (CWs). Our research quantified ARGs (sul1, qnrS, and blaCTXM32), class one integron (intI1), and bacterial marker (16S) in four recirculating v...

Waters contaminated with micropollutants are of environmental and public health concern globally. Stormwater is a significant source of anthropogenic micropollutants to receiving waters. Hence, sustainable stormwater remediation is needed to reduce contamination of waterways. Yet designing sustainable bioremediation solutions, including those targe...

Microalgae were employed to remove nutrients from a pre-treated wastewater (so-called anaerobic membrane bioreactor effluent, AnMBR effluent) over a 24-day semi-continuous cultivation with varied N:P ratios. NH4⁺-N reduction percentage ranged from 68 to 94% with average removal rates varying from 8 to 26 mgN·L⁻¹d⁻¹ at different stages. Total phosph...

Hydrothermal carbonization (HTC) of raw and anaerobically digested (AD) manure with either water or whey was studied, with the goal of recovering energy and nutrients. Specifically, the impacts of HTC reaction temperature (180–240 °C), solid feedstock, and type of liquid on hydrochar quality and aqueous phase properties were tested. Of the hydrocha...

To reduce public health hazards, greywater reuse may involve disinfection, which is often performed through chlorination. The formation of toxic disinfection by-products is a negative side-effect of chlorine’s reaction with organic matter, of which trihalomethanes (THM) are one of the most dominant (though not most toxic) groups. Greywater treatmen...

A near-zero waste treatment system for food processing wastewater was developed and studied. The wastewater was treated using an anaerobic membrane bioreactor (AnMBR), polished using an outdoor photobioreactor for microalgae cultivation (three species were studied), and excess sludge was treated using hydrothermal carbonization. The study was condu...

Aquaponics plant waste, such as the non-edible parts of many vegetable crops, can be a source of environmental pollution, while its treatment might cause an economic burden. Therefore, efficient use of this waste would be advantageous.This study aimed at investigating anaerobic digestion of aquqponic lettuce waste to recover nutrients and energy th...

Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and disinfected for securing user health. This research studied at the laboratory scale, and in flow-through setups, which are generally used in full-scale GW treatment the disinfection efficiency of the two commonly used technologies (a) chlorination and (...

Lately, there has been a growing interest in converting low-cost biomass residuals, including wastewater sludge, into char-like materials for various applications. In this research, ammonium (NH4+) adsorption and desorption potential of hydrochar activated via Fenton oxidation were systematically investigated. Hydrochar was prepared from domestic w...

The conversion of poultry litter to hydrochar has been proposed for stabilization of the soils and to eliminate pathogens. Still, research on the hydrochar's effect on soil properties as a function of production temperature, and its direct use with plants is limited in general and even less so on poultry litter. We characterized poultry litter hydr...

In abattoir operation, paunch waste can present a major problem when flushed with water and discharged. Collected and processed separately, it provides a means of reusing organic carbon and nutrients. Hydrothermal carbonisation (HTC) is a means to process the waste that overcomes some problems of composting and anaerobic digestion. Experiments were...

Water-Food-Energy (WFE) resources exert mutual influences upon each other and thus cannot be managed separately. Information on household WFE expenditures addresses knowledge that distinguishes between geospatial districts' social welfare. Social welfare and investment in districts' WFE resources are interconnected. District (node) product of WFE n...

The COVID-19 pandemic has severely impacted public health and the worldwide economy. Converging evidence from the current pandemic, previous outbreaks and controlled experiments indicates that SARS-CoVs are present in wastewater for several days, leading to potential health risks via waterborne and aerosolized wastewater pathways. Conventional wast...

On-site in-vessel composting of sewage sludge is considered to be applied in Israel for peripheral wastewater treatment plants (WWTPs). Based on lab-scale simulations using municipal sewage sludge and green waste, this study identifies a prospective range of values related to biomass stabilization during short-term processing. Within two weeks, 26-...

The conversion of poultry litter to hydrochar has been proposed for stabilization of the soils and to eliminate pathogens. Still, research on the hydrochar's effect on soil properties as a function of production temperature, and its direct use with plants is limited in general and even less so on poultry litter. We characterized poultry litter hydr...

Recovery of nutrients, such as ammonia, from wastewater offers an attractive approach to increase the overall sustainability of waste management practices. Conventional wastewater treatment processes require significant energy input, and the useful form of nitrogen (ammonia), is usually lost. Ammonia, a major component of fertilizers, is convetiona...

Phosphorus (P) is an essential element for life that is introduced through feed in modern aquaculture—the fastest growing food production sector. P can also be a source of environmental contamination and eutrophication if mistreated. Fish assimilate only 20–40% of the applied P; the rest is released into the water. The goals of this research were t...

Aquaculture contributes to global food security, producing over 70 million tons of fish and aquatic products annually. Protein rich fish feeds, together with labor costs are the most expensive component costs in aquaculture. Feed application is given as percent of fish weight and therefore, reliable biomass assessment is essential for profitable an...

Hydrothermal carbonization (HTC) has received much attention in recent years as a process to convert wet organic waste into carbon-rich hydrochar. The process also generates an aqueous phase that is still largely considered a burden. The success of HTC is dependent on finding solutions for the aqueous phase. In the present study, we provide the fir...

Recirculating aquaculture systems, as part of aquaponic units, are effective in producing aquatic animals with a minimal water consumption through effective treatment stages. Nevertheless, the concentrated sludge produced after the solid filtration stage, comprising organic matter and valuable nutrients, is most often discarded. One of the latest d...

Use of recirculating aquaculture systems (RAS) to grow fish is on the rise. Fish feed typically contains 25–60% protein and is the only significant input in RAS. Fish recover 20–30% of the applied feed as biomass, and the unassimilated nitrogen is released into the water, mainly as ammonia, which is toxic to fish. Nitrification is the most common t...

This study represents the first systematic attempt to evaluate antibiotic-resistant bacteria (ARB) occurrence in treated greywater and the potential spread of these bacteria from the greywater to greywater-irrigated soil. Treated greywater from three recirculating vertical flow constructed wetlands, each located in a household in the central Negev...

Detailed assessment of hydrochar wetting properties, which could provide an essential understanding of underlying mechanisms during its application to soils, is lacking. We characterized hydrochar produced from hydrothermal carbonization (HTC) performed on poultry litter at various temperatures and for different times in terms of hydrophobicity and...

Poor sanitation due to improper treatment of human excreta, and energy scarcity are global problems with only partial solutions. Thus, feasible conversion of human excreta into safe, reusable “products” and renewable energy could be advantageous. The research objectives were to study the properties and major chemical processes occurring during hydr...

There is a recognized need for mineralizing aquaculture-derived sludge in aquaponics systems in order to reduce waste production. Many recent studies of aquacultural waste treatment have focused only the production of biogas as opposed to the potential for mineralization of nutrient-rich sludge. Upflow anaerobic sludge blanket (UASB) reactors provi...

Greywater reuse can significantly reduce domestic water consumption. While the benefits are promising, risks are still under debate. Using a quantitative microbial risk-assessment model, we assessed the health risks associated with greywater reuse. The pathogens Salmonella enterica, Shigella spp., and Staphylococcus aureus were evaluated due to the...

The development of intensive recirculating aquaculture systems (RAS) with low water exchange has accelerated in recent years as a result of environmental, economic and other concerns. In these systems, fish are commonly grown at high density, 50 to 150kg/m3, using high-protein (30%-60%) feeds. Typically, the RAS consists of a solid treatment and a...

Growing amounts of poultry litter call for improved treatment solutions. Its conversion to renewable energy can offer a solution while concomitantly reducing environmental impact and reliance on fossil fuels. We compared the production and combustion of biochar by slow pyrolysis to that of hydrochar by hydrothermal carbonization (HTC) in terms of c...

Understanding and optimization of composting processes can benefit from the use of controlled simulators of various scales. The Agricultural Research Organization Composting Simulator (ARO-CS) was recently built and it is flexibly automated by means of a programmable logic controller (PLC). Temperature, carbon dioxide, oxygen and airflow are monito...

We examined the effects of sex, age, and reproductive state of the insectivorous bat Pipistrellus kuhlii on the abundance and prevalence of arthropod ectoparasites (Macronyssidae and Cimicidae) in habitats with either sewage-polluted or natural bodies of water, in the Negev Desert, Israel. We chose water pollution as an environmental factor because...

Greywater (GW) reuse for irrigation is a common method of reducing domestic consumption of fresh water. Most of the scientific research and legislation efforts have focused on GW's health risks, while less attention has been given to its environmental outcomes. One of the environmental risks of GW irrigation is its possible effect on soil hydraulic...

Expansion of dryland agriculture requires intensive supplement of organic fertilizers to improve the fertility of nutrient-poor desert soils. The environmental impact of organic supplements in hot desert climates is not well understood. We report on seasonal emissions of nitrous oxide (N2O) from sand and loess soils, amended with limed and non-lime...

Food security, specifically in water scarce regions, is an increasing local and global challenge. Finding new ways to increase agricultural production in a sustainable manner is required. The current study suggests a conceptual model to integrate established recirculating aquaculture practices into a near-zero discharge aquaponic system that effici...

Millions of decentralized graywater-reuse systems are operating worldwide. This water is directly accessible to household inhabitants, raising environmental and public health concerns. Graywater may contain a variety of harmful organisms, the types and numbers of which vary with source-type, storage time, and background levels of infection in the c...

Cryptocaryon irritans, a marine protozoan fish parasite with a life cycle that includes cyst formation, constitutes a major concern in intensive recirculating aquaculture systems (RASs), due to its potential propagation in a system with high fish density and minimal water change. In this study, the survival of C. irritans in sludge collected from a...

The practice of decentralized, on-site greywater (GW) treatment, the non-toilet portion of domestic wastewater (WW) stream, has become widespread with millions of systems in use worldwide. GW reuse can bring a signifi cant reduction in domestic and urban water demands and increase the exploitation e ffi ciency of this scarce resource. However, environ...

In response to increasing demand for aquaculture products and strict new regulations on organic matter and nitrogen discharge, inland closed recirculating aquaculture systems (RASs) are being developed as a viable eco-sustainable alternative to traditional aquaculture (e.g. ponds, raceways and cages) because of their minimal environmental impact an...

A sensitive, high-throughput, and cost-effective method for screening bacterial pathogens in the environment was developed. A variety of environmental samples, including aerosols, soil of various types (sand, sand/clay mix, and clay), wastewater, and vegetable surface (modeled by tomato), were concomitantly spiked with Salmonella enterica and/or Ps...

Graywater reuse is rapidly gaining popularity as a viable source of reclaimed water, mainly for garden irrigation and toilet flushing. The purpose of this study was to determine, by epidemiological survey, the risk for gastroenteritis symptoms associated with graywater reuse. The study comprised a weekly health questionnaire answered by both graywa...

Disease outbreaks are a major concern in aquaculture. This is particularly true in intensive recirculating aquaculture systems (RASs), due to the high rearing densities in a system where high concentrations of organic matter are produced with minimal water exchange. This study assessed the survivability of the common fish pathogen Streptococcus ini...

Greywater Reuse examines the features and implications of greywater reuse scientifically, quantitatively, and thoroughly. Based on the authors' extensive studies of treatment facilities in urban and rural environments, development of greywater treatment systems, and research of potential environmental and health risks posed by greywater at differen...

This comprehensive text describes the chemical, physical, and microbial properties of greywater. It covers the treatment and removal of greywater pollutants, providing case studies of common methods. It also identifies the risks involved and proposes regulatory measures to help reduce these risks, reviewing the greywater management strategies, poli...

Disposing of nitrate-containing effluents from seawater-fed intensive aquacultural applications is a major environmental problem. A possible solution is to mix nitrate-rich effluents from marine recirculating aquaculture systems (RASs) with citrate-rich liquid wastes (CLW), a common by-product of the food industry. Where possible, such strategy can...

Natural bodies of open water in desert landscapes are important resources for survival of desert-dwelling animals and in recent years artificial bodies of water may have become equally important. In the present study we are testing if species richness and activity of bats are related to the water chemistry both in natural and artificial bodies of w...

Reuse of greywater (GW) has raised environmental and public health concerns. Specifically, these concerns relate to onsite treatment operated by non-professionals; systems must therefore be reliable, simple to use and also economically feasible if they are to be widely used. The aims of this study were to: (a) investigate GW treatment efficiency us...

Ammonia emissions from poultry-manure disposal and agricultural applications pose a global environ-mental challenge that requires the development of proper management practices. Recently, a schemecomprised of a compost-based biofilter for the treatment of high loads of ammonia emitted from poultry-manure digestion (up to 500 g NH3m−3biofilter day−1...

A main concern with reuse of treated domestic wastewater (DWW) in irrigation is its possible effect on the soil. Few studies have focused on DWW treated in on-site settings, which generally use low-tech systems that can be constructed and serviced locally. One such system is the recirculating vertical flow constructed wetland (RVFCW). The aim of th...

Reuse of graywater (GW) for irrigation is recognized as a sustainable solution for water conservation. One major impediment for reuse of GW is the possible presence of pathogenic microorganisms. The presence and abundance of six pathogens and indicators were investigated in three GW recirculating vertical flow constructed wetland treatment systems...